The Duchess of Cambridge, Kate Middleton, joined Sir Ben Ainslie at the launch this morning of the four-time Olympic champion's America's Cup team.

Having become the first Briton since Charlie Barr in 1903 to sail on a winning America's Cup boat when he helped Oracle Team USA to their dramatic 9-8 win over Team New Zealand in San Francisco last autumn, Sir Ben Ainslie launched the British team which he hopes will see Britannia rule the waves once again in the oldest international sporting trophy.

The Duchess of Cambridge, a keen sailor who beat her husband 2-0 in a head-to-head aboard America’s Cup yachts during their recent tour of Australia and New Zealand, attended a private breakfast at The Royal Museums in Greenwich before the launch, meeting key investors and team members.

The America's Cup was born in the foaming Solent off the Isle of the Wight back in 1851. The inaugural trophy was lost to the Americans and has never been seen again in this country.

Ainslie, the most successful Olympic sailor of all time with four golds and a silver to his name, hopes to change that with a British team based in Portsmouth sailing under the flag of Yacht Squadron Racing, a club affiliated to the Royal Yacht Squadron.

"This is the last great historic sporting prize never won by Great Britain," Ainslie said at the launch. "It has always been my ambition to mount a home challenge. The time is right and I am hugely encouraged by the support we are getting, not least from the Duchess of Cambridge.

"I learned a great deal aboard Oracle in San Francisco and I would not be challenging if I did not believe we have a real chance of winning this time."

Since returning from San Francisco last autumn Ainslie has been working furiously behind the scenes to attract investment and talent to his team.

The 37 year-old has been helped by two of Britain’s most passionate amateur sailors in Sir Charles Dunstone, co-founder of Carphone Warehouse, and the entrepreneur Sir Keith Mills, the deputy chairman of the London Organising Committee of the 2012 Games.

Both men were involved in the British America’s Cup bid Team Origin that also involved Ainslie and have taken on the directorial roles as well as providing funding.

Sir Charles Dunstone, Chairman of BAR’s Board said: "This campaign is about righting a wrong. We have never won it. We have an amazing maritime history. The Cup has to come home, we have to do that."

All systems go: The Duchess of Cambridge was in Greenwich this morning for Sir Ben Ainslie's America's Cup team launch

Ainslie has signed a number of experienced designers to help build the AC62 wingsail catamaran with which he hopes to wrest back the trophy from Oracle Team USA.

One name that has not yet joined is Red Bull design genius Adrian Newey. Newey is "keen" to help, but has not yet committed to his Amercia's Cup project, according to Ainslie.

Newey recently signed a new deal at Red Bull that will see him step back from the Formula One project and allow him time to indulge other interests.

"Adrian has taken a great deal of interest in the development of the team and would be a tremendous asset if he chooses to get involved," Ainslie said.